Multi-detector row computed tomography and blunt chest trauma

Blunt chest trauma is a significant source of morbidity and mortality in industrialized countries. The clinical presentation of trauma patients varies widely from one individual to another and ranges from minor reports of pain to shock. Knowledge of the mechanism of injury, the time of injury, estimates of motor vehicle accident velocity and deceleration, and evidence of associated injury to other systems are all salient features to provide for an adequate assessment of chest trauma. Multi-detector row computed tomography (MDCT) scanning and MDCT-angiography are being used more frequently in the diagnosis of patients with chest trauma. The high sensitivity of MDCT has increased the recognized spectrum of injuries. This new technology can be regarded as an extremely valuable adjunct to physical examination to recognize suspected and unsuspected blunt chest trauma.     

Multi-detector computed tomography of acute abdomen

Acute abdominal pain is one of the most common causes for referrals to the emergency department. The sudden onset of severe abdominal pain characterising the acute abdomen requires rapid and accurate identification of a potentially life-threatening abdominal pathology to provide a timely referral to the appropriate physician. While the physical examination and laboratory investigations are often non-specific, computed tomography (CT) has evolved as the first-line imaging modality in patients with an acute abdomen. Because the new multi-detector CT (MDCT) scanner generations provide increased speed, greater volume coverage and thinner slices, the acceptance of CT for abdominal imaging has increased rapidly. The goal of this article is to discuss the role of MDCT in the diagnostic work-up of acute abdominal pain.     

棉花烟雾吸入性急性肺损伤大鼠模型的建立

目的建立大鼠烟雾吸入性急性肺损伤动物模型。方法24只雄性SD大鼠随机分成对照组及3h、6h、24h组,每组6只。对照组无烟雾吸入,3h、6h、24h组分别在烟雾吸入3、6、24 h后行血气分析及炎症因子、组织学检查。结果烟雾吸入组大鼠血气分析示氧合指数小于300,符合急性肺损伤诊断标准,炎症细胞因子较对照组明显升高（P<005）;组织学检查示肺内出现肺水肿,炎症细胞浸润明显。结论通过烟雾发生装置给予大鼠吸入一定时间棉花制造的烟雾,可以成功制作烟雾吸入急性肺损伤动物模型。     

烟雾吸入性肺损伤后吸入一氧化氮对早期中性粒细胞活性氧的影响

目的 研究大鼠烟雾吸入性肺损伤后吸入20 ppm的一氧化氮(NO)对中性粒细胞(PMN)活性氧的影响.方法 72只雄性Wistar大鼠,体重为250～350g,随机分入Ⅰ、Ⅱ及Ⅲ组,每组各24只.各组再按伤后6、12及24小时3个时相点均分为3组.另取8只大鼠以同样方法致烟雾性损伤,测定伤后1小时伤后值.再取另外8只非致伤大鼠测定伤前值.除了伤前值组大鼠外,其余各组均复制成重度烟雾吸入性损伤模型.Ⅰ、Ⅱ及Ⅲ3组分别于致伤后2小时开始应用动物呼吸机进行定容机械通气,Ⅰ组吸入空气,Ⅱ组吸入氧气(FiO2=0.4),Ⅲ组除吸氧外(FiO2=0.4)再吸入20ppm NO.处死大鼠后制备肺组织匀浆.用试剂盒测定肺组织活性氧水平(ROS)及肿瘤坏死因子α(TNF-α)含量.数据均采用SPSS10.0统计软件包进行完全随机设计方差分析,结果用(x)±s表示.结果 伤后肺组织匀浆ROS含量均升高.伤后6小时及12小时时,3组之间无显著性差异(P＜0.05).至24小时,Ⅱ组较Ⅰ组降低(P＜0.05),Ⅲ组较Ⅰ组降低更为明显(P＜0.01),Ⅲ组亦低于Ⅱ组(P＜0.05).TNF-α含量伤后明显升高,伤后12小时及24小时,Ⅲ组均低于Ⅱ组(P＜0.05).ROS与TNF-α含量正相关性明显(r=0.442,P＜0.01).结论 吸入浓度为20 ppm的NO能抑制烟雾吸入性损伤大鼠的PMN产生ROS.     

Multi-detector row computed tomography: imaging in acute aortic syndrome

Acute aortic syndromes (AAS) encompass a spectrum of emergencies. These include those non-traumatic disease entities of the aorta namely, penetrating atherosclerotic ulcer, intramural haematoma, dissection and aneurysm rupture. The various types of AAS cannot be reliably differentiated on clinical grounds alone. Acute thoracic aortic injury is usually included in this group even though clinical presentation is different, i.e., in the context of trauma, the imaging features are very similar. Differentiation of AAS from acute coronary syndrome (ACS) is important, however, it must be remembered that ACS may occur as a result of AAS. Now electrocardiogram (ECG)-gating technology is widely available, ECG-gated multi-detector row computed tomography (MDCT) is a powerful clinical tool in the acute emergency setting, which enables rapid and specific diagnosis of aortic pathology. ECG-gated MDCT significantly reduces motion artefact, avoids potential pitfalls in diagnosis and often provides diagnostic information about the coronary arteries. It should be used as a first-line imaging technique. This article examines the role of MDCT imaging and cardiac gating in the assessment of AAS and discusses the differentiation of this spectrum of aortic diseases with reference to the key imaging findings as obtained by experience in our institution.     

Diagnosis of acoustic neuroma with computed tomography

Summary Sixty-one acoustic neuromas were examined with computed tomography (CT). For differential diagnosis the tumors were thoroughly analyzed for manner of growth, shape, volune, calcification, attenuation pattern, contrast enhancement, presence of peripheral edema, and cisternal deformation.     

Multi-detector computed tomography angiography of the hepatic artery in liver transplant recipients

Purpose: To evaluate the ability of multi-detector row computed tomography angiography (CTA) in detecting hepatic artery complications in the follow-up of liver transplant patients, performing volume-rendering as reconstruction technique.

Material and Methods: The anatomy of hepatic artery was studied in 27 liver transplant recipients with a four-row CT scanner using the following parameters: collimation, 1 mm; slice width, 1 mm; table feed, 6-8 mm/s; spiral reconstruction time, 0.5 s; reconstruction interval, 0.5 mm; mAs, 160; kVp, 120. Before the study, the patients received 1000 ml of water as oral contrast agent to produce negative contrast in the stomach and the small bowel. A non-ionic contrast medium was infused intravenously at a rate of 5 ml/s with a bolus tracking system. Volume-rendering of hepatic artery was performed with the 3D Virtuoso software.

Results: The celiac trunk, the hepatic artery, and the right and left hepatic arteries were successfully displayed in high detail in all patients. Side branches, including small collaterals, and hepatic artery anastomosis could also be readily visualized. Volume-rendered CTA detected six hepatic artery stenoses, two hepatic artery thromboses, and two intrahepatic pseudoaneurysms. In two cases, CT detected hepatic artery stenosis with a diameter reduction of less than 50%, while digital subtraction angiography showed a normal artery.

Conclusion: Volume-rendered multi-detector CTA is a promising non-invasive technique, since it allows images of high quality to be generated with excellent anatomical visualization of the hepatic artery and its complications in liver transplant recipients.     

Multislice spiral computed tomography to determine the effects of a recruitment maneuver in experimental lung injury

Although recruitment of atelectatic lung is a common aim in acute respiratory distress syndrome (ARDS), the effects of a recruitment maneuver have not been assessed quantitatively. By multislice spiral CT (MSCT), we analyzed the changes in lung volumes calculated from the changes in the CT values of hyperinflated (V_HYP), normally (V_NORM), poorly (V_POOR) and nonaerated (V_NON) lung in eight mechanically ventilated pigs with saline lavage-induced acute lung injury before and after a recruitment maneuver. This was compared to single slice analysis near the diaphragm. The increase in aerated lung was mainly for V_POOR and the less in V_NORM. Total lung volume and intrathoracic gas increased. No differences were found for tidal volumes measured by spirometry or determined by CT. The inspiratory-expiratory volume differences were not different after the recruitment maneuver in V_NON (from 62±18 ml to 43±26 ml, P=0.114), and in V_NORM (from 216±51 ml to 251±37 ml, P=0.102). Single slice analysis significantly underestimated the increase in normally and poorly aerated lung. Quantitative analysis of lung volumes by whole lung MSCT revealed the increase of poorly aerated lung as the main mechanism of a standard recruitment maneuver. MSCT can provide additional information as compared to single slice CT.     

Point-of-care ultrasound detection of tracheal wall thickening caused by smoke inhalation

Smoke inhalation is the leading cause of death due to fires. When a patient presents with smoke inhalation, prompt assessment of the airway and breathing is necessary. Point-of-care ultrasonography (US) is used for the rapid assessment of critically ill or injured patients. We herein present a case report of a 54-year-old male who was transferred to the emergency department with shortness of breath, coughing, carbonaceous sputa, and rhinorrhea after inhaling smoke caused by a fire in his locked bedroom. He had no surface burns on the face and no edema or erosion in the oral cavity. He had hoarseness without stridor. His breath sounds were positive for expiratory wheezes. Laryngoscopy showed light edema and erosive findings on the supraglottic region. Bedside point-of-care US revealed hypoechoic thickening of the tracheal wall. The thickening was confirmed by a computed tomographic scan. The patient was carefully monitored with preparation for emergency airway management and was treated with supplemental oxygen and an aerosolized beta-2 adrenergic agonist in the intensive care unit. The symptoms were subsequently relieved, and reexamination by US after 2 days showed remission of the wall thickening. Point-of-care US may therefore be a useful modality for the rapid diagnosis and effective follow-up of tracheal wall thickening caused by smoke inhalation.     

酚妥拉明和地塞米松对吸入性损伤大鼠肝脏损伤的保护作用及机理

目的　观察酚妥拉明和地塞米松对重度吸入性损伤大鼠肝脏损害的保护作用及机制。方法　将 72只大鼠随机分为A、B、C 3组。对照组 (C组 )腹腔注射生理盐水 ,A组腹腔注射酚妥拉明 ,B组腹腔注射地塞米松。另取 6只非致伤大鼠做伤前值测定 ,再取 6只致伤大鼠 ,伤后 30分钟做伤后值测定。结果　C组谷丙转氨酶 (GPT)、总胆红素 (TBIL)、丙二醛 (MDA)、MDA/超氧化物歧化酶 (SOD)及组织含水量 (WCT)均明显增高 ,组织中一氧化氮 (NO)水平较伤前值变化不大 ,SOD、ATP水平降低。A组和B组中TBIL、GPT、MDA、MDA/SOD、NO明显低于C组 (P <0 .0 1 ) ,A组ATP和SOD明显高于C组 (P <0 .0 1 ) ;B组SOD高于C组 (P<0 .0 1 ) ,B组的ATP则与C组差别不显著 (P >0 .0 5 ) ,B组肝组织含水量低于对照组 (P <0 .0 1 )。结论　酚妥拉明与地塞米松均可能通过调节机体的NO水平进而提高机体抗氧化能力和能量代谢 ,从而对重度吸入性损伤后大鼠的肝脏起保护作用。在改善能量供应和降低MDA方面酚妥拉明效果优于地塞米松     

烟雾吸入伤后内皮素─1水平的变化及意义

目的：观察大鼠烟雾吸入伤后血浆及支气管肺泡灌洗液（ＢＡＬＦ）中内皮素。１（ＥＴ－１）含量的动态变化，以探讨其与急性吸入性肺损伤发生发展的关系。方法：采用大鼠烟雾吸入伤模型，分别检测了正常对照及致伤２、６、１２和２４小时动物的动脉血气、肺水量、静态肺顺应性（Ｃｓｔ）、ＢＡＬＦ中总蛋白（ＴＰ和白蛋白（Ａｌｂ）、以及血浆和ＢＡＩＦ中ＥＴ－１量。结果：动物吸入伤后出现急性呼吸衰竭和严重肺水肿，Ｃｓｔ显著降低，ＢＡＩＦ中ＴＰ及Ａｌｂ进行性升高；血浆及ＢＡＬＦ中ＥＴ－１水平亦明显增加，且血浆ＥＴ－１的变化与Ｃｓｔ及ＢＡＬＦ中ＴＰ的改变相关显著。结论：ＥＴ－１在烟雾吸入伤后肺血管通透性增加和肺功能损害中可能有重要作用。     

Multi-detector computed tomography in the diagnosis and management of acute aortic syndromes

Acute aortic syndrome (AAS) is a spectrum of conditions, which may ultimately progress to potentially life-threatening aortic rupture. This syndrome encompasses aortic dissection (AD), intramural haematoma, penetrating atherosclerotic ulcer and unstable thoracic aortic aneurysms. Multi-detector CT (MDCT) is crucial for the diagnosis of AAS, especially in the emergency setting due to its speed, accuracy and ready availability. This review attends to the value of appropriate imaging protocols in obtaining good quality images that can permit a confident diagnosis of AAS. AD is the most commonly encountered AAS and also the one with maximum potential to cause catastrophic outcome if not diagnosed and managed promptly. Hence, this review briefly addresses certain relevant clinical perspectives on this condition. Differentiating the false from the true lumen in AD is often essential; a spectrum of CT findings, e.g., “beak sign”, aortic “cobwebs” that allows such differentiation have been described with explicit illustrations. The value of non enhanced CT scans, especially useful in the diagnosis of an intramural hematoma has also been illustrated. Overlap in the clinical and imaging features of the various conditions presenting as AAS is not unusual. However, on most instances MDCT enables the right diagnosis. On select occasions MRI or trans-esophageal echocardiography may be required as a problem solving tool.     

Using <Superscript>99m</Superscript>Tc-DTPA radioaerosol inhalation lung scan as compared with computed tomography to detect lung injury in blunt chest trauma

Background

Detection of pulmonary contusion in patients with blunt chest trauma is very important so as to commence therapy immediately to avoid irreversible damage. The purpose of our study was to evaluate the efficacy of technetium-99m diethylene triamine pentaacetic acid (^99mTc-DTPA) aerosol inhalation lung scintigraphy in comparison with chest computed tomography (CT) in the diagnosis of pulmonary contusion at acute blunt chest trauma.

Methods

Twenty-nine patients with isolated blunt chest trauma were referred to the emergency department of our hospital, and nine healthy people participated in this study. Sixteen patients who had pulmonary contusion on CT scans were referred to as group 1, and 13 patients who had normal CT scans as group 2. Nine healthy people comprised a control group. ^99mTc-DTPA aerosol inhalation lung scintigraphy was performed on the first day in all patients.

Results

The mean half time (T_½) and penetration index values of ^99mTc-DTPA clearance were significantly lower in groups 1 and 2 compared with the control group. Among the three groups, there were no significant differences in arterial blood gas analysis except for PO₂. The mean T_½ value of ^99mTc-DTPA clearance did correlate with PO₂ values but not with pH, PCO₂, or HCO₃ values.

Conclusions

^99mTc-DTPA radioaerosol inhalation lung imaging may serve as a useful adjunct and supportive method to chest CT scanning for detecting mild pulmonary contusion.

     

Multi-detector row computed tomography: imaging the coronary arteries

Over the last 2 years, multi-detector row computed tomographic (MDCT) cardiac imaging has continued to rapidly develop and evolve from the experimental research setting to become a useful clinical tool. The increasing availability of MDCT presents today's clinicians with an additional non-invasive diagnostic cardiac imaging method, in particular for the coronary arteries. With the advent and increasing clinical use of 16-detector row machines, and now with the imminent clinical emergence of 64-channel machines, the improvements in spatial and temporal resolution and sophisticated ECG-gating are allowing motion-free, fast, accurate, detailed, contrast-enhanced cardiac imaging that begins to approach the accuracy of traditional invasive diagnostic techniques. Additional diagnostic information may also be provided.     

Timing of exposure in angiographic computed tomography

Visualization of heart chambers or the abdominal arterial phase on one of two CT-scans was achieved in 89.4% of 169 injections (91 patients) using only 30 ml of contrast medium (370 mg iodine/ml), when the start of scanning was accurately timed at predicted bolus peak concentration. Normal arrival times and numer of transit cycles to the bolus concentration maximum in the right (RV) and left ventricle (LV) after injection of a small radionuclide bolus of technetium-99 m were related to the patient's heart rate (HR) in a group of 200 patients. For the RV, mean arrival times varied significantly between 2.31 (HR: 90–109 beats per minute) and 3.46 seconds (HR: 50–59 beats per minute), mean number of transit cycles between 4.1 and 3.5. For the LV, mean arrival times varied significantly between 6.92 (HR: 90–109 beats per minute) and 11.37 seconds (HR: 50–59 beats per minute), and the mean number of transit cycles between 11.5 and 10.7. Washout from the LV lasted between an average of 9.2 (HR: 90–109 beats per minute) and 8.5 cycles (HR: 50–59 beats per minute). Contrary to actual transit times, there was no significant difference in the number of transit heart cycles for heart rates between 60 and 109 beats per minute, so that to determine the scan starting time, the patient's cycle length (60 divided by heart rate) had only to be multiplied by the corresponding normal value of transit cycles, i.e., four for the RV, 11 for the LV, and 13 for the abdominal arteries. By applying the estimated values, the result was negative on two successive scans in only 10.6% because of failure in coordination on the part of the operators or bolus transit delays (due to severe heart failure, severe lung disease, recent thoracotomy, or small veins disease). With automatic triggering of the scanner by a timer and injector and with a flush of saline after injection, results can be further improved. Radionuclide studies supported by grant of the Internal Department of the Government of the Federal Republic of Germany     

Multi-detector computed tomography (MDCT) imaging of cardiovascular effects of pulmonary embolism: What the radiologists need to know

Background

Patients with pulmonary embolism have high mortality and morbidity rate due to right heart failure and circulatory collapse leading to sudden death. Multi-detector computed tomography MDCT can efficiently evaluate the cardiovascular factors related to pulmonary embolism.

Limitations of computed tomography for diagnostic Neuroradiology

Summary The limitations of computed tomography for diagnostic Neuroradiology are pointed out. The relation of CT to the classical neuroradiological examinations are discussed.     

Left-sided perforated acute appendicitis in an adult with midgut malrotation: the role of computed tomography

We report a case of left-sided perforated acute appendicitis in the patient with midgut malrotation. Embryology, clinical findings, and radiological presentation are discussed. Highly prevalent disease presents here in the unusual location and thus in the unusual presentation. The emergency room physician and radiologist should be aware of these unique clinical presentations so that appropriate surgical intervention may be initiated promptly.